Prior art in the area of multiple rotor engines and pumps have sought to create the most efficient apparatus possible. Close tolerances between the moving parts, a maximizing of the displacement within the apparatus, and an improved valve system for the transfer of gases or liquids into the displacement area, have been a continuing effort. Prior inventions have sought to attain the goal of greater efficiency with varying results.
In U.S. Pat. No. 3,207,425 (Morse), an engine with multiple rotors was shown. In this engine, there is interaction between a plurality of rotary piston vanes which are mounted in an offset manner to a revolving member, and where the piston vanes move to increase or decrease the volume of a centrally located area. Incorporated into this invention are a series of valve discs which allow the movements of pressurized gases through the engine. As the vanes are offset, this invention is subject to both revolving and reciprocating unbalances. This invention also only provides for one central area of positive displacement, with any peripheral changes in volume not subject to providing energy through positive displacement.
U.S. Pat. No. 3,234,888 (Wise) was an improvement in rotary pumps, where the vanes, having been described as impellers, revolved around a central shaft that was provided for each impeller. A rather convoluted series of passageways was incorporated into this invention through the impellers, so as to provide for an exchange of pressure between a central area and peripheral area during the pumping process. Rotational movement of the impellers caused the various passage ways to be either blocked on one end or open on both ends to provide an exchange of pressure. This system did not meet the desired efficiency for a rotary pump however, due to the imperfect valve system.
In U.S. Pat. No. 3,439,654 (Campbell), improvements with regard to positive displacement in internal combustion engines was shown. Various intake ports and transfer ports were provided, which allowed pressurized gases to move through the system during operation. Further advancements were seen in U.S. Pat. No. 3,799,126 (Park), in which multiple rotors were shown with an improved orientation to each other. Valve port assemblies were described as being open to one separate compartment only at any one time, and the ports themselves were defined in part by the rotors, in that no separate port opening and closing apparatus was used apart from said rotors.
Further development is seen in U.S. Pat. No. 4,324,537 (Meyman), in which a plurality of rotors were used to provide compression during rotational movement. Rotors in this invention were more triangular shaped than elliptical. A separate disk was provided which allowed an inlet and outlet port to be rotated around the revolving rotors to provide access to the central and peripheral cavities. In this invention, a single rotating disk is used, which was an improvement over prior inventions, but still did not meet the desired efficiency between rotors and valve system operations.
U.S. Pat. No. 4,422,836 (Meyman), also showed a rotary machine which depicted improvements in an end face sealing plate. This invention had the drawbacks of undesired wear on the end bases of the rotors and covers. No new improvements in intake ports and/or exhaust ports were given.
Further inventions sought to expand on the idea of an improved valve system. In U.S. Pat. No. 4,934,325 (Snyder), a rotary internal combustion engine was shown, in which four adjacent rotors were provided with hollow interior flow passages that allowed communication of pressure changes between the central and peripheral areas within the housing.
U.S. Pat. No. 5,341,782, (McCall) depicted a rotary internal combustion engine, which was provided with four oval shaped rotors. Two of these rotors had a truncated end to periodically open the working volume to exhaust gases and to intake fresh air. This invention did not allow for a maximizing effect of the gas exchange between the interior and the exterior areas around the rotors. This invention would not operate as effectively as desired for purposes of pumping liquids or gases, since the design and operation of the rotors require an increase of pressure before any venting could occur.
An invention which allows for close tolerances between revolving rotors, a maximized displacement, and a coordinated valve system will provide the greatest efficiency. This invention is directed to these goals, having a coordinated improved valve system to accommodate a maximum displacement, and rotor configuration.